Apparatus for diffusion molding

ABSTRACT

An apparatus for diffusion molding cubical granules of metal into a workpiece. Tooling is assembled to form the shape of a mold cavity which contains the cubically-shaped metal granules to be diffusion molded. Collapsible supports space the tooling from the interior walls of an envelope containing the tooling. Pressure bars, slidably engaged with the walls of the mold cavity, transmit compressive force applied on the envelope to the metallic granules. The envelope is sealed and evacuated to facilitate oxide and contaminate-free diffusion molding. The method for diffusion molding cubically shaped metal granules into a workpiece comprises cleaning the granules, depositing them into the cavity of a tooling mold, vibrating the tooling mold to orient the interfaces of the cubical granules into alignment with one another, encapsulating the tooling mold in a sealed enclosure, evacuating the enclosure, applying heat and pressure to the enclosure to effect diffusion molding of the granules into a workpiece configuration, and removing the workpiece from the enclosure and reusable tooling mold.

O United States Patent 1 m1 3,743,455 Green July 3, 1973 APPARATUS FORDIFFUSION MOLDING [75] Inventor: Eugene D. Green, La Mesa, Calif. [57]ABSTRACT An apparatus for diffusion molding cubical granules of [73]Asslgnee' gfg g gg i Corporation San metal into a workpiece. Tooling isassembled to form g the shape of a mold cavity which contains thecubical- [22] Filed: Sept. 30, 1971 ly-shaped metal granules to bediffusion molded. Col- Appl. No.: 185,111

Primary ExaminerRobert L. Spicer, Jr. Attorney-John R. Duncan lapsiblesupports space the tooling from the interior walls of an envelopecontaining the tooling. Pressure bars, slidably engaged with the wallsof the mold cavity, transmit compressive force applied on the envelopeto the metallic granules. The envelope is sealed and evacuated tofacilitate oxide and contaminate-free diffusion molding. Y i

The method for diffusion molding cubically shaped metal granules into aworkpiece comprises cleaning the granules, depositing them into thecavity of a tooling mold, vibrating the tooling mold to orient theinterfaces of the cubical granules into alignment with one another,encapsulating the tooling mold in a sealed enclosure, evacuating theenclosure, applying heat and pressure to the enclosure to effectdiffusion molding of the granules into a workpiece configuration, andremoving the workpiece from the enclosure and reusable tooling mold.

10 Claims, 6 Drawing- F igures" svAcuArme rum \ n 14 so 70 12 CHEMICALLYCLEANWG CUBICAL GRANULES TO E DIFFUSION MOLDED ASSEMLIMG ?00L8N6COMPONENTS IN PARTEALLY ASSEBLED ENCLOSURE 0F ENCAPSULATING A$8EMBLYHEAT TREATING ENCAPSULATING ASSESLY T0 PALE YELLOW HEAT DISCOLOR FLUSMNGASSEMBLY WITH INERT GAS VIBFQNI'ING ASSEMBLY TO ORIENT ALIGNMENT OFGRANULE INTERFAOE$ COPLETENG ASSEMBLY AND SEALHNG ENCAPSULA'HNG $$EBLYEVACUATING ENCAPSULATING A$$EMBLY 0mm: compwssssom LOADENG F ASSEMBLY1'0 mnucs DBFFUSION Momma 0F CUBICAL GRANULES DESA$$EMBLINGENCAPSULATION AND REQVINGMFFUSION MOLDED WORKPiECE The present inventionis particularly concerned with the production of high density parts andstructural shapes by diffusion molding homogeneous metal granules in avacuum pack mold. Metal granules usually are irregular in shape andconsequently do not lend themselves for use in diffusion molding of highstrength members due to the low density of the molded end product.Although diffusion does occur between the individual granules regardlessof shape, the finished product lacks the density of the base material ofthe granules. Voids and pockets form in the diffused material as aresult of the irregularity of the interfaces of adjacent individualgranules. Upon magnification of the finished part, voids are readilydiscernable, regardless of the size of the granules used.

SUMMARY OF THE INVENTION Thediffusion molding apparatus of the presentinvention comprises an enclosure containing tooling for diffusionmolding metal granules into a structure or workpieces. The individualcomponents of the tooling are arranged to define a mold cavity in whichmetal granules to be diffusion molded are contained. The tooling isspaced from the interior of the enclosure by a plurality of collapsiblesupport members which serve to permit synchronized movement of selectindividual tooling components during the diffusion molding operation.Pressure members extend into the mold cavity in slidable engagement withthe walls thereof to transmit compressive force applied to the vacuumpack enclosure directly on the column of granules contained within thecavity. A conduit communicates with the interior of the enclosure toprovide means for purging and evacuating the enclosure immediately priorto its use in diffusion molding.

In preparing the diffusion molding apparatus for use, the entire packassembly, i.e-., enclosure, collapsible supports, tooling, and pressuremembers, are first chemically cleaned by immersing in a suitablecleaning solution to remove all traces of contamination. Thereafter thetooling components are heat treated to a temperature and for a timesufficient to grow a tight oxide coating thereon. The oxide coatingserves as a stop-off or parting agent to facilitate disassembly of thetooling components and removal of the workpiece from the tooling mold.The coated tooling components may then be assembled on the enclosurebase resting on the collapsible supports. The tooling is arranged suchas to define a mold cavity having a configuration commensurate with thedesired shape of the workpiece. The diffusion molding apparatus or packassembly is now ready for filling with molding material.

The molding material as used in the-above described apparatus may befabricated by one or more methods in order to produce metallic granulesof cubical shape.

Exemplary of one method of fabrication is by slicing av length of squarein cross section material into equal lengths. The granules produced bysuch method are thereafter chemically etched and thereafter retained ina cleaning solution until such time as they are transferred tothe moldcavity of the apparatus. One retention solution suitable for thispurpose is methylethyl ketone.

Subsequent to the assembly of the components of the coated tooling intothe desired configuration, a measured quantity of cleaned granules istransferred from the retention solution into the cavity of the toolingmold. Depending on the particular shape desired, additional toolingcomponents may then be added to complete the tooling assembly asrequired to manufacture the more complex configurations. Usually wherecomplex shapes are to be molded, an additional measured quantity ofcubical granules is transferred from the cleaning solution into thenew-formed cavities created by the additional tooling. In the preferredmethod of diffusion molding, the tooling mold is continuously vibratedduring the transfer'or filling operation in order to orient theinterfaces of the individual cubes into alignment with one another.After filling the mold to a predetermined level, suitably cleanedpressure members in the form of strips or bars are slidablyinserted inthe cavities of the tooling mold with a pressure face thereof in directcontact with the interface of the loose cubical granules and anoppositely disposed pressure face outstanding from the mold cavity. Withthe pressure members in position, the enclosure is completed bypositioning a cover plate to rest on the outstanding pressure face ofthe pressure members and installing side closures around the sides incontact with the base and cover. The side closures are secured to thebase and cover by continuous welds extending along the abuting edges ofthe base to closure and cover to closure. A conduit having one endcommunicating with the cavity of the tooling mold and the opposite endthereof connected to a supply source of inert gas such as Argon,conducts the gas into'the enclosure during welding of the side closurein order to avoid contaminating the tooling components and moldingmaterials as a result of oxidation. After the enclosure is properlysealed and tested against leakage, air is evacuated through the conduitwhereupon the area thus evacuated is thoroughly flushed with alternatecycles of evacuation and back flushings with inert gas injected into theenclosure under pressure through the conduit. Upon completion of theflushing operation, the Argon gas is evacuated and a vacuum developedand maintained throughout subsequent operations by sealing the end ofthe conduit as by hot forging. The completed pack assembly is nextheated until the total pack and its content are uniformly heated to thetransition temperature of the metallic granules contained in the mold.While elevated to this temperature, a compressive force is applied tothe enclosure of suffieient magnitude to cause collapse of the sideclosure of the enclosure thereby reducing the total pack thickness andforcing the pressure members to penetrate deeper into the mold cavity.As the application of compression force continues, the pressure memberspenetrate deeper into the vertical mold cavities compressing thegranules until the enclosure cover limits penetration by engaging themold cavity tooling. Thereafter, further movement of the cover resultsin collapse of the collapsible supports under certain of the toolingcomponents to effect diffusion molding of the granules contained in themold cavities which lie in horizontal or out of vertical planes tocomplete fabrication of the diffusion molded workpiece. The enclosure isthen cooled and disassembled to remove the oxide and contaminate-freefinished workpiece.

It is an object of the present invention to provide an apparatus andmethod for diffusion molding of metallic granules into a workpiece inwhich the density thereof is equivalent to the density of the metallicgranules.

Another object of this invention lies in the reusability of thecomponents of the mold apparatus.

Still another object of this invention is to provide a diffusion moldingapparatus and method byv which workpieces of complex and difficultconfigurations may be manufactured. I

Yet another object of this invention lies in the ability of theapparatus to transform compression force to a multi-directional force onthe material being diffusion molded.

Another object of this invention is to provide an apparatus and methodby which parts and workpieces may be manufactured in a finishedcondition without requirement for subsequent machining operations.

Other objects and advantages of the present invention will become moreapparent in consideration of the following detailed description in whichlike reference numerals designate like parts of the invention throughoutthe several views of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view, partly insection and in phantom, of the encapsulation assembly of the presentinvention.

' FIG. 2 is a cross-sectional view taken along line 22 of FIG. 1.

FIG. '3 is a cross-sectional view similar to FIG. 2 showing a furtherembodiment of the present invention, and,

FIG. 4 is a cross-sectional view similar to FIG. 2 showing a stillfurther embodiment of the present in vention.

FIG. 5 is a cross-sectional view similar to FIG. 2 showing anencapsulation pact assembly for diffusion molding a further modifiedform of a workpiece.

FIG. 6 is a block flow diagram of the steps of the method of the presentinvention.

Referring now to FIGS. 1 and 2, an encapsulation pack assembly generallydesignated by the numeral 10, comprises an enclosure 12 having a baseplate 14, sides 16, and a cover plate 18. The sides 16 are fabricatedfrom a lighter gauge material than that of the base plate 14 and coverplate 18 in order to provide for deformation thereof as occurs duringdiffusion molding and as will be hereinafter further discussed.Positioned in the enclosure 12 is the tooling generally designated 20which defines the configuration of the mold cavity. In the embodimentillustrated in FIGS. 1 and 2, the mold cavity for the desiredconfiguration of the finished workpiece P is substantially U-shapedhaving a centrally located flange or rib C intermediate side flanges Sdepending from a flat web or bottom portion B. Transverse flangefmembersT integral with and depending from web portion B, connect central flangeC with side flanges S. One endof the U-shaped workpiece P is closed byend flange member E which is also integral with and connects to web Band flanges C and S.

The tooling 20 necessary to produce the workpiece P comprises a moldbottom plate 22 which rests on the base plate 14 of the enclosure 12.Surrounding the bottom plate 22 is a yoke member 24 which is spacedabove base plate 14 by a plurality of collapsible supmushroom-shapedhaving a shank or stem portion and an enlarged head portion. The shankportion bottoms in a counterbored recess 30 in the base plate 14 tomaintain the yoke member 24 elevated a distance above the surface of thebase plate 14 prior to the diffusion molding operation. Supports 28 areelongated members having a su stantially T-shaped cross-section.Elongated T-shaped recesses'32 in the base plate 14 receive the verticalbar of the supports 28 to maintain elevation of the yoke 24 to theelevation established by the supports 26. Although the supports 26, 28elevate the yoke 24 above the base plate 14, it is to be noted that theelevation height does not exceed the thickness or gauge of the bottomplate 22 in order to effect a slight overlap condition therewith. Yokemember 24 as viewed in plan, (FIG. 1), is of picture frame configurationhaving internal walls 34 and 36 slidably engaged and partiallyoverlapping with mating edges of the bottom plate 22. Walls 34 and 36form one side and one end wall of the external walls of the cavity mold.The external cavity mold wall opposite wall 34 is the face 38 of a sidebar 40 while the external cavity mold wall opposite wall 36 is the face42 of a transverse side bar 44. Side bar 40 is spaced above base plate14 by the collapsible supports 28 at an elevation commensurate with thatof the yoke 24. A wedge-shaped bar 46 sandwiched between an innerinclined wall 48 of the yoke 24 and an outer inclined wall 50 of theside bar 40 serves to maintain side bar 40 in sliding overlappingengagement with a mating edge of the bottom plate 22.

Transverse side bar 44 is similarly spaced above base plate 14 bycollapsible supports 28 and is maintained in sliding overlappingengagement with a mating edge of the bottom plate 22 by a wedge-shapedbar 52 similar to the bar 44 interposed between inclined walls of yoke24 and bar 44.

The individual components of the encapsulation pack assembly 10 ashereinbefore described, are preferably fabricated from a suitablenon-corrosive material such as stainless steel. Thus the probability ofcontamination due to outgassing is minimized or entirely eliminated asmay otherwise occur with the use of other materials whenthey are heatedto the transition temperature of the metallic granules of the workpiece.

Upon assembly of bottom plate 22, yoke 24, collapsible supports 26, 28,side bars 40, 44 and wedge bars 46, 52 on base plate 14, a measuredquantity of cubical granules is deposited on bottom plate 22 to form theweb B of the workpiece P. Support tooling 54, 56, 58, 60, 62 and 64 .ofdimensions allowing for the desired thickness of workpiece flanges C, E,S and T, are positioned on the cubical granules of web B whereupon themold cavities for these flanges are filled with a measured quantity ofcubical granules to the height desired. Pressure member 66 is a unitarygrid'structure, or a grid structure formed of individual bars or stripswhich rest on the cubical granules that form the flanges C, E,

v S, and T of workpiece I. If desired, pressure member 66 may beattached directly to, or made integral with the cover plate 18 of theenclosure 12. Pressure member 66 projects out of the mold cavities tospace cover plate 18 of enclosure 12 from the tooling 20. Sides 16 ofthe enclosure 12 are joined to base plate 14 and cover plate 18 byvacuum seal welding along the pheripheral edges thereof.

An important feature of the present invention is the orientation of theinterfaces of the cubical granules into alignment with one another toeffect a uniform checkerboard pattern. In order to effect this alignmentthe pack together with the mold tooling and associated components, iscontinuously vibrated as the loose cubical granules are poured into themold cavities. The vibration continues until such time as the moldcavities are filled and settling of the granules is complete. Thereafterthe pressure members 66, cover plate 18 and sides 16 may be assembled ashereinbefore described.

A conduit 68 projects through side 16 and yoke 14 to selectively conductan inert gas 72 such as Argon into the encapsulated pack assemblythrough a valve 70. The inert gas is supplied under positive pressure tothe entire assembly during the assembly to protect the surfaces of thecubical granules to be diffusion molded from oxidation or the like.After the enclosure 12 is sealed, inert gas is pumped into the innervolume thereof in and around the tooling and molding material. The packassembly is then evacuated through the evacuation valve 74 by anevacuation pump 76 in communication with the conduit 68. Duringevacuation, inert gas 72 is used to flush the inner volume of theencapsulation pack assembly 10 and to dispel unwanted gases and moistureand the like from the interior thereof.

Prior to assembly, the individual parts of the encapsulation packassembly are heated to a degree by which the parts are discolored to apale yellow. This is the lowest color in the tempering color spectrumand reflects a thin oxide coating on the surfaces of the metal parts.This oxide coating does not adhere to the cubical granules joined duringthe diffusion molding process and thus the coating facilitateseconomical disassembly of the encapsulated assembly. Accordingly, theencapsulation pack, including tooling and collapsible supports, isreusable in continued repetitive production.

The metallic cubical granules used in molding the workpiece P must befree from contamination in order to assure proper diffusion of theindividual granules to one another. Consequently in preparation fordiffusion molding, the granules are chemically etched and subsequentlyimmersed in a suitable retention solution such as methylethylketone. Thegranules are retained in the retention solution until such time as theyare transferred into the mold cavity of the encapsulation pack assembly.

After the encapsulation pack 10 has been suitably sealed and flushedapproximately 3 or more cycles of evacuation and backflushing with aninert gas, a final vacuum is drawn on enclosure 12 by opening valve 74in communication with the evacuating pump 76. Upon reaching a vacuumreading of approximately 10' mm of mercury, valve 76 is closed and theconduit 68 is sealed by hot forging while the assembly is under vacuum.The. evacuation, conduits, valves, inert gas, and evacuating pump arethus disconnected from the encapsulation pack by severing and sealingthe exposed end of the conduit 68. The entire diffusion mold pack isthen placed in a suitable furnace having accurate temperature controlswhich are set to, but not exceeding a temperature that is slightly belowthe transition temperature of the material of the cubical granules ofthe workpiece. After maintaining the pack at this temperature for a timesufficient to permeate all pack components, the pack assembly is removedand pressure is applied against cover plate 18 and base plate 14 byutilization of a mechanical press or the like. This moves the platestowards one another, forcing pressure members 66 into their respectivecavities in the tooling 20 until the cover plate 18 engages the tooling20. Continued application of pressure results in the collapse of thecollapsible supports 26, 28, into their respective recesses 30, 32 asthe tooling, i. e., yoke 24, side bars 40, 44, wedge bars 46, 52 andsupport tooling 54-64, moves towards base plate 14 and bottom plate 22.As previously generally discussed, the sides 16 are of a lighter gaugedeformable material which is adapted to deform or bow without rupture ofits welded connections as the thickness of the pack assembly is reduced.Movement of the cover plate 18 towards the base plate 14 is limited byengagement of the yoke 24 with the base plate 14. Thus the compressionforce applied to cover plate 18 and base plate 14 is transmittedsequentially through pressure members 66 into the flanges C, E, S, and Tof the workpiece P, and thereafter into the web B thereof to diffusionmold the cubical granules into a workpiece of a uniform densitycommensurate with the density of the base material of the workpiece. Theassembly is then removed and allowed to air cool after which the vacuumseals are broken and the assembly is disassembled to remove theflnished'workpiece.

In the embodiment illustrated in FIG. 3, there is shown a workpiececonfiguration identical inall respects to the configuration of FIG. 2except for the addition of T-shaped stiffeners F on the flanges S and C.The tooling yoke is substantially similar to the yoke 24 of FIGS. 1 and2 except for the addition of a notch or recess 102 in which a portion ofthe flange stiffener F is formed. Side bar 104 is similarly providedwith a notch'or recess 106 wherein the overhand portion of the flangestiffener F is formed. Support tooling generally designated 108 isdivided into three segments in order to permit removal upon disassemblyof the encapsulation pack assembly. Mold bars 110 having a notch orrecess 112 to form an opposite overhang portion of the flange stiffenersF, are spaced from one another by wedge members 114.

The T-shaped stiffeners F of the flanges S and C are formed with anintegral pressure bar 116 of the same basic material as the cubicalgranules, diffusion molded to the flange and stiffener granules.Pressure members 118 similar to pressure members 66 of FIGS. 1 and 2,are slidably positioned in the cavities forming the stiffeners F asdefined by the recesses 102,-106, and 112 of yoke 100, side bar 104, andsupport tooling 108 respectively. These integral pressure bars 116 servein a dual function in the diffusion molding of the workpiece of FIG. 3.Initially bars 116 act as a pressure member in the same manner as thepressure members 118 to exert compression force on the loose granulescontained in the cavities of the flanges C and S. Thereafter they becomean integral part of the flanges C and S of the finished product orworkpiece. Thus the loose cubical granules contained within the recesses1 02, 106, and 112 of the, tooling, when acted upon by pressure member 118 while heated to the transition temperature, diffuse to the sides ofthe bars 116 to form the T-shaped stiffeners F of the flanges C and S.

form to the shape desired. The bottom surface of the support tooling 302is similarly angled to parallel the incline of the upper surface of themold plate 300. In this modification, the mold bottom plate 300 extendsoutwardly towards the sides 304 of the enclosure under the yoke 306. Therecesses 308 and 310 for the collapsible supports 312 and 314respectively may be machined in mold plate 300-as shown in FIG. 4, or ifdesired, the bottom plate 316 of the enclosure may be made integral withthe mold plate 300.

The workpiece disclosed in FIG. is of I-beam configuration havingflanges C depending from a web B intermediate end flanges S. Enclosure400 together with yoke 402, side bar 404, wedge bar 406, collapsiblesupports 408, 410, and pressure members 412, are substantially identicalin construction detail to like components 24, 40, 46, 26, 28, and 66respectively as described in connection with FIGS. 1 and 2. Plate 414 issimilarly identical in construction to the mold bottom plate 22 of FIGS.1 and 2 with the exception that recesses 416 are provided therein toreceive collapsible supports 418. Support tooling generally designated420, comprises upper tooling 422 and lower tooling 424. Lower tooling424 is elevated above plate 414 by the collapsible supports 418. Uppertooling 422 is spaced directly above lower tooling 424 by a measuredquantity of cubical granules as required to obtain the desired thicknessof web B of workpiece P. Lower pressure members 426 in verticalalignment with pressure members 412, rest on plate 414 and extendupwardly therefrom into sliding engagement with the mold cavity walls asdefined by yoke 402, side bar 404, and lower tooling 424.

In diffusion molding of the workpiece P of FIG. 5, the toolingcomponents including plate 414, yoke 402, side bar 404, wedge bar 406,collapsible supports 408, 410, lower pressure members 426, collapsiblesupports 418, and lower tooling 424 are assembled on the base of theenclosure 400 in the arrangement as shown in the drawing. It is to benoted that all the encapsulation pack components will have been properlytreated prior to assembly to remove all traces of contaminating foreignmatter as previously described in connection with the encapsulation packof FIGS. 1 and 2. A measured quantity of cubical metal granular is thentransferred from a holding receptacle containing a suitable cleaningfluid, into the cavities of the mold up to the level of the web B.During the transfer operation, and continuing through the entire moldcavity build-up, the pack assembly is continuously vibrated to align theinterfaces of the cubical granules with one another to effect acheckerboard alignment pattern. After filling the mold cavity to thelevel of web B, the upper tooling 422 is positioned on the granules ofweb B in vertical alignwith Argon gas and evacuated in the manner. aspreviously described for the FIGS. 1 and 2 embodiment.

Exemplary of the material particularly adaptable to diffusion molding istitanium. Although it has been well documented that titaniumis anexcellent candidate metal for diffusion molding, the method involved fortitanium applies to other metals as well. However, it

should be noted that the pressures and heat ranges under which diffusionoccurs for a particular metal or metal alloy may vary accordinglywithout affecting the method as described in detail as follows andillustrated in block diagram form in FIG. 6.

Cubical granules of metallic material are chemically etched to remove altraces of oxide and contaminates from all surfaces thereof andimmediately immersed in a retention solution until prior to placement inthe cavity of the diffusion mold pack. The retention solution ashereinbefore discussed, may be one of several commercially availablesolvents such as methylethylketone or de-ionized water. The cleanedgranules are maintained submerged in the retention solution until suchtime as they are to be placed in the diffusion mold cavity. Thisprotects'the surfacesof the cubical granules to be joined to one anotherfrom oxidation and contamination.

The encapsulation assemblies of FIGS. 1 through 5 each include elementsthat are structurally similar to one another. Consequently thepreliminary preparation common to eachwill be described using theembodiment shown in FIGS. 1 and 2 as the drawing reference.

Prior to assembly, the individual parts of the encapsulation assemblyare heat treated to obtain the previously described oxide coating. Thiscoating provides for reusability of the assembly components in additionto serving as a parting agent to facilitate disassembly thereof forremoval of the finished diffusion molded workpiece. The preliminarypreparation further includes fusion welding of the conduit 68 to theyoke 24.

The encapsulation assembly components are now assembled as previouslydescribed in the order shown in the drawings. The cleaned granules aretransferred into the mold cavities in a measured quantity after beingair dried with Argon gas. During the transfer operation, theencapsulation assembly is continuously vibrated while Argon gas isconducted into .the assembly through the conduit 68. Upon filling of themold cavities to the proper level, the pressure members 66 areinstalled, and cover plate 18 positioned thereon. Sides 16 are nextwelded in place .to seal and complete the assembly.

As previously discussed, the vibration of the encapsulation assemblyduring and after the transfer of granules into the mold cavity is ofprime importance in producing high quality, high density moldedstructures or workpieces. The vibrating machineused for such purpose maybe of a commercial type which is adjustable so as to vibrate at aselected frequency over a wide range of frequencies. Such vibration isto insure that the cubical granules are properly oriented into acheckerboard pattern whereby the resultant molded structure will be ofmaximum density .of the basic metal of the individual granules Theembodiments described above and shown in the accompanying drawings areillustrative of specific forms of the present invention. The presentembodiments are therefore to be considered in all respects illustrativeand not restrictive, and all changes which come within the meaning andrange of equivalency of the claims are therefore intended to be embracedtherein.

What is claimed and desired to be secured by Letters Patent is:

l. A diffusion molding apparatus comprising:

an enclosure having a base, cover, and side closures, said cover beingspaced from said base by said side closures, said side closures beingdeformable, said spacing between said cover and base being reduced upondeformation of said side closures, tooling encapsulated within saidenclosure, said tooling having internal walls defining the shape of acavity in which diffusion molding material is contained, collapsiblesupport means spacing said tooling from an adjacent interior surface ofsaid enclosure, a pressure member slidably engaging said internal wallsof said tooling, said pressure member projecting into said toolingcavity into contact with said diffusion molding material, said diffusionmolding material being compressed into said tooling cavity by saidpressure members to mold a workpiece upon deformation of said sideclosures and collapse of said support means. 2. The diffusion moldingapparatus of claim 1 in which:

internal tooling is positioned within said cavity of said tooling, saidinternal tooling 'having external walls,

said internal walls of said tooling and said external walls of saidinternal tooling defining the cavity in which said diffusion moldingmaterial is contained. 3. The diffusion molding apparatus of claim 1 inwhich:

at least one of said internal walls of said tooling is movable. 4. Thediffusion molding apparatus of claim 2 in which:

said pressure member slidably engages the external walls of saidinternal tooling.

5. The diffusion molding apparatus of claim 2 in which:

said pressure member slidably engages said external walls of saidinternal tooling and said external walls of adjacent of said internaltooling. 6. The diffusion molding apparatus of claim 2 in which:

collapsible support means space said internal tooling from saidenclosure. 7. The diffusion molding apparatus of claim 2 in which:

' at least one of said external walls of said internal tooling ismovable. 8. The diffusion molding apparatus of claim 1 in which:

said collapsible support means engages said base of said enclosure andsaid tooling. 9. The diffusion molding apparatus of claim 1 in which:

said-pressure member engages said cover of said enclosure. 10. Thediffusion molding apparatus of claim 1 in which:

said pressure member engages said base of said enclosure.

1. A diffusion molding apparatus comprising: an enclosure having a base,cover, and side closures, said cover being spaced from said base by saidside closures, said side closures being deformable, said spacing betweensaid cover and base being reduced upon deformation of said sideclosures, tooling encapsulated within said enclosure, said toolinghaving internal walls defining the shape of a cavity in which diffusionmolding material is contained, collapsible support means spacing saidtooling from an adjacent interior surface of said enclosure, a pressuremember slidably engaging said internal walls of said tooling, saidpressure member projecting into said tooling cavity into contact withsaid diffusion molding material, said diffusion molding material beingcompressed into said tooling cavity by said pressure members to mold aworkpiece upon deformation of said side closures and collapse of saidsupport means.
 2. The diffusion molding apparatus of claim 1 in which:internal tooling is positioned within said cavity of said tooling, saidinternal tooling having external walls, said internal walls of saidtooling and said external walls of said internal tooling defining thecavity in which said diffusion molding material is contained.
 3. Thediffusion molding apparatus of claim 1 in which: at least one of saidinternal walls of said tooling is movable.
 4. The diffusion moldingapparatus of claim 2 in which: said pressure member slidably engages theexternal walls of said internal tooling.
 5. The diffusion moldingapparatus of claim 2 in which: said pressure member slidably engagessaid external walls of said internal tooling and said external walls ofadjacent of said internal tooling.
 6. The diffusion molding apparatus ofclaim 2 in which: collapsible support means space said internal toolingfrom said enclosure.
 7. The diffusion molding apparatus of claim 2 inwhich: at least one of said external walls of said internal tooling ismovable.
 8. The diffusion molding apparatus of claim 1 in which: saidcollapsible support means engages said base of said enclosure and saidtooling.
 9. The diffusion molding apparatus of claim 1 in which: saidpressure member engages said cover of said enclosure.
 10. The diffusionmolding apparatus of claim 1 in which: said pressure member engages saidbase of said enclosure.